SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f32d6f3ee6cba9434cab7fd0e5997e3bf07fc0bd802501e5bd8bc129c8d4ed29' 
  AND token = 'kl6cbF6Ty6wnJX7sdxFMMxlvK57rpNsm4Qkc8IvU2oI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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