SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36d3a5e37fd2754f18d7ea960afe4f4007e89c7f536ae24f51930fa059eee912' 
  AND token = 'qHMXcsZlnfeJeSZ1KcNTnkXGMPHGi2dmquhdJZ2xuOU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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