SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5476aa1fb51e9c7ab210fc888d62ebf526b63f34534ee8f4dc3293686fb3ceab' 
  AND token = 'XOIrw8egkI5+eTzglkj4BwlubfCHix8EWqRAeeLk4TA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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