SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01ea6101bed3c3fdfec4c49096e777f24168fbfb11650aea3213a771433dcd7b' 
  AND token = 'HLxoBSxH/HQse0u3Wz8Y7Yc+mtltEaGTiMKvDk6im3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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