SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a63afeb5d2742f25fc89606e0a1c55d2a5e752fbdaf5ae3b2c66f3c3e308575' 
  AND token = 'zCNKWUBorfLPzv5Fb8jVn0GGsRrtTlCtq/N3w6rXxog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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