SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3295144626cbadc4a729a3096af6ab5b39e137751154960783ef75b69782f50' 
  AND token = 'DVdrnWe0aHDAcGVdta4ZZruW5tfsDYuFzdgO1gpndv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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