SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fbd7fdb4c36db187f8964295e7ac0261d50c565f156efe250db8138ace280d00' 
  AND token = 'Bs3NjEsgwAyXdwTPKUAaNWOtmwtk/aeq0A8eBxZq6Z4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}