SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b069aa2eb10ed6eea37e487f99a99c737849dae0df73b3064a8ee39358c2b6f' 
  AND token = 'bG5U39tW1tjTBVXzq8ELCGsH9gcQYNaO9Xiigiy+fQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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