SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe91f3639d3f91bcc63d278dd7f747bed0bff912956cf8960b8c79680f5b7b24' 
  AND token = '3w5LO6yB37VLDPQssivr4GyPMu1y+Vf0woHIyz/UWWY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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