SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aafd52fe0eee37d2a93dc6061b5ebca973c95a98424aeb72beb17d2d3abaf95' 
  AND token = '8FX/KgEFoEjZHlBG5fr9HLNqnUFKea+3G3KjsfsZ00o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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