SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49d2c6ed07ddf0541daa087da78537bf36032ebcd0129f6e41b92603f80bfd4a' 
  AND token = 'MYPiGYQ5izbixa4xPvYLvWyzD1lohttPc3vXcFQRwfM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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