SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd455804dedec987e47d8473d294be39b71af053f1cba3d68ee19c979d24688e8' 
  AND token = 'QLZSgcROuYJASSxp34Whl39i/oIJZ3k7DIncWcAg4VE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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