SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f9c5d00be0ddd288e24715dbfc9d8284df462335fc2885aa0d6bb772bd715148' 
  AND token = '2O6DscQ6vs94GV8OWlv0slEb/K9syJRxvUroF5sKbGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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