SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f632638c2ef63f4ed7ae46c6062e061fc5069efb412643094d605a6c2427cf45' 
  AND token = 'pn1TTUGzmPNADM9eYaauILiCAQo6xhhaMnC31kwO+18=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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