SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98aa512b969a598567b0fd219a210d50231d5035adc035f9fbf726fdbe089014' 
  AND token = 'bKrfaMHkU4L9fMPUWJ73i78QZzdyJuUibIQJKOWXAd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}