SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e701f99e74c2495a0632d9ab3c9a516eea487246d457ed8547b8052fe653813' 
  AND token = 'MdXbrl1QMtJDXIwFjZVykkELN0Xlf/Tyc00b55nIODc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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