SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54c70b04b98cde78e5a2d9f0f642d7f2f83b4b3a268fdac65048c29f9b255708' 
  AND token = 'rF1O8nPuvnSzX6sSuIphnHMAUX/RO6BQvso61PKBpDI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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