SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4f6cfb8489a9eea1afee7b2671595139fba466f82aa9af0b12ac2bb788fb484' 
  AND token = 'K/yJjvVhZvLxelCx0QF+cd0onjce6RHyFJnECgfVgCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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