SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '2bca0b3bedcc4a30e4bf34071561ec8d5c286e5b1acb5316ad4cf7abbb4a2e87' 
  AND token = 'pCmu2oNVzUxzJwXbBZ5kattm3//ntoCA2uljjsd5UAo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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