SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c692df2afbe0ac1f65303c57c804ee6e1c61890671043ed01b3aeb7190f0640c' 
  AND token = '2BK45ZHeWK8ZJLP3COfDxX54jrrpxZXzEwvwFt0A5Eo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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