SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca83351e24aaed189cfc50c22bdcd1adb455bf1a8c696afa442d14632cc2734d' 
  AND token = 'mYFDBiaPjtJzzBOm1rAK9G4S66aGoGbnAVorVpJJkys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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