SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8084108c66fb68572c18589a1b0b44841ef0f361a7ad4c2f70b902fa18db324a' 
  AND token = 'nwQJsTNMnkk+rL+ZX20UFFSX5cr2XfGM/6kBTm2JuOs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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