SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e5bd67e48f8498f1fffaf2c40e67ceb6ca942136f36da395d327dfa6170be1da' 
  AND token = 'xqdagHfqr1eSFIo6UDMVI81D/dyUu53uXZRovT0i6Jg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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