SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc334e48e1396b26dd7782783ea0611efb3d42520d5f5377dc957cdf35c09e18' 
  AND token = 'ejwvFC2Nz1ootZt+/Xfljc8PRNImRNJO3HOdx1ouGQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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