SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '91eced008cbdf6a72b7fa1b901f281a88ae9aa2915261b7d43b91d31ec90faaf' 
  AND token = 'FryaZJGGB53ogT2+0PvigCvtm5XwCOKL2kWPwzECFUY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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