SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd98b66641b0ff0d0ee07268b7125d7954d5d549a50dc04fff702a63c5a78883' 
  AND token = 'EU0k2l9Vw11AFY2vb/WiWX8zW3woH7Us3ilHsryKQEM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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