SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4891d4adbc8d3a371376e84985f2f090443c20ba46b99d6ed60a495a4a2b3c4' 
  AND token = 'zDNBhmUPYh/28xT4ooM3AEpbTgTUq48bPJuLpkF/1WM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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