SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ed77ac17855281bc00b8ce40b2b31a39ee7902e9828c948156bb473a52f3eff6' 
  AND token = 'om7pO0pZXxNsjV7iCqxv+NK0Ts6anMwQ2/lpJvBUtcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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