SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea48c3011da12bed22df7925a89f5292d62cbaf5beafab9f5bed0f2b7fcb3bbf' 
  AND token = 'J3Z/iO2aAcZwiItfKcJeYdHyjMx2hL13HSv5zbG8M5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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