SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b42b5109887a825e9d8cf9c3c207a48c95deacce436e964b3ab4081d3204d561' 
  AND token = 'wGq9Quy8IlSX4GLHL+FumT+Qf2MGckdh9f/PonBc1D0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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