SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8efdf3152a1bbbb7c0dfa7bf099b1e4aa6e0b2246f5399bb9e8574fe629869ac' 
  AND token = 'uzKX/IJdJzP6IVQicEP8ZlYc+1N5UP5S61V3jYJG/cE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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