SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e5c8cad08d4f824073134a1f3398c716f6abcee7340402f1c485d1756b329824' 
  AND token = 'ctbzoxyqMfTyf/JUQE3icoN2fbW+KBWB4SxJqjpnDpk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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