SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '575b553cca84bdd6c319f103dc40be6237581bf4978be159201a656f3d99880e' 
  AND token = 'P+Xl67d24bfYFVVy5C0H0CEuqu8oJI+/1Mo9AxiSmys=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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