SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '25218888cfb1d17d38282904aeb468164f93394aa67ac3f00514fecf3d287352' 
  AND token = 'C6JbPHypQXI0qkmcHbrEAtdnlcMTkA/B6wUwoQYaALc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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