SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea778b64756b1a377605ec1d1eed2f5137fb1b9fb1ee42981e60a19cc9303938' 
  AND token = 'My4A23y+DiRsuaxMzONN0LiQYJWCHJItdX3itU5f8+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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