SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ac47d9d32cb072aae0e819e1ef64630aa2525e470ca677353f6adbbea054161' 
  AND token = 'PLBOcjIMxH0+QBqr3DI6c/cXmWlBantwLu1r7jYKYVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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