SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ee1aaa4638ac5a1d695627082fcea6db1122c0a09937412b0e8957ee398464f' 
  AND token = 'JSUCNIKKOf6HzfJuqPBt+h6J9w7hCNV4rlRhvnz5Q6A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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