SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6a661f231fbf9e74db2fca6225e4fd7dbd20aeadc04839347897fbffebef72c' 
  AND token = '8MZFvJXcpVNihPTsk8y0OxS9hLMqb6eRjSaWAoBIelk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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