SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49cdf71310dfcbb0b5d332431534e1ca0a215bbeb87424fe8c21256793414525' 
  AND token = 'C8s2MRxglsknPYmVduPKddAclNx6l/V9sQuzhtP6JBw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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