SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '376bd67f8d67579f40983b19120c526372dba2f95098705141294b507516de3d' 
  AND token = '7WFV7tHy78xc96vTHrD1hs095rttURa9T6UTzUhKdTQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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