SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf35410eafb7cc0ace9d6ad91d73e19c44655f112f4a56652a214d0dda84421c' 
  AND token = 'OKRJ4hkUSreBfGEJ8qy2JxSqfXDcO0zEIECuPrkcyMo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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