SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd351b71f1a213dfff6f19fc630bacc2ff572425846318a6f2085ff11f67c0029' 
  AND token = 'uXYXiHsykKvr1Wg6gpATtZn613MIoy71u2a2hsqD6OI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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