SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '166b982528b7fe0aa9127a55171d06489d6fa93c95b8d9a59a272225163956df' 
  AND token = 'rdQclEySmHEasnXtgV34kpg8D3mXpGWzr3SGmp1GrPc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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