SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7834bef452938e4d31a22b6d897a169bf3bb99b1339bb6303c604650cebb3a26' 
  AND token = 'swgJDXJgmyyBp5feK2Mlh0haAWdbfMLDz5W+sRrAIXQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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