SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe37af44ab8692e27ce65ff50259a21f8b8af5e2c4d6b8c0f9dd4321d38453fb' 
  AND token = '9WVDTCJyHINrF0zzRWBdBn+w9juVvgVrrPpV87haBw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}