SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49b3ccce4a89b0da8772f6700652cda5f6918962af75048c0491d05889d600f7' 
  AND token = 'Li2mdyAZXQ7KEDiVgV2xGjWlq8o2PT6liNqOsEP8pvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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