SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaf47b4daa8674de7cdea8260a15ac0728cf7a40637eafe6452e7cc792ef5b1c' 
  AND token = 'ZtA5mRQe+2YYrh6StTSnmQtlMxe4tfXcN/8gzEEeBWI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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