SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7fc3226446ee20bbc967343336dd8cbaebbae334048ffa050b4494b41d244f3' 
  AND token = 'LLbYTF9izEWDnVbD8q9WgN8kJe+O4lDVCRtiTIIfYN8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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