SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cd37a3c514ee1fbebd2f91a79b2f55afef15bf662406e389f84a1a05c278b829' 
  AND token = 'zEqI7GoTEoARpXhSuQR8o/773zmZAx4oOtsP3R6Egzc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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