SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84d7156ac50cff311f0c5ea1e82c168bce3e874b7495ba0d097385db52087c1a' 
  AND token = 'aQkmSHJfPyvoK3oLJh1gw6NxTm/tkCuuJB2uaBsoCjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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