SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c090128a9f60fa274e69dd6687d38d382806b2e87bdb6fc1c768fb84d4112acd' 
  AND token = 'vsLL7QJl1/HRJXbJNaGPYjFZqHZuPoTtf2KeFqDY2Jk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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