SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cbb5fda04b575bbcf528be6c14e485cfde18a78022c0240fd79f55e58e425e26' 
  AND token = '1BUxO34vQxLGuOT9rhEmqsZ7cLAWF+fTaxIffmJPhHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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