SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4dc2d5b6105588adc09aefb23e101c49bd96c2d6bcbadcd8f51308f33cda3391' 
  AND token = 'AAxssjHrOenO2N9fiS1hNEU49N0LkspxNIHFAxTHhqc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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