SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7bd4b1b04a1a3b218aae282418006445129c1c583961dac0697ffb9386923f5' 
  AND token = 'fZKtsww4SmuTyGbZW//Vovm99UKZqH00r8+s6lMYF/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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