SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abec0c73b31186916d81be65e2c0b76035e13215dc0387d132f5c371698c7e44' 
  AND token = 'npSUyApIUj6Eh8L3h3zch3ZbT7y61tbTdhhq9Cys+fY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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