SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5fdadf490ebce98b11875ea8636c3aad8e1bf61c86b73dbf37ab55217a0d820b' 
  AND token = '3F5t+HD6k647IGP/Yyxgif/Tde8wrzN8FrRbnNTlYHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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