SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f762133d985cf83b13be80f14887c223b1570dbd9a8fd46164d8e0e204975631' 
  AND token = 'Nl8iMlgR1LAZaRb7bNrd1OyF1o9FIlnLKmtdVgOQ0Dw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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