SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '910fbfbe8fdadd581d7c809f329bfa66a58fbc0cd57de840ba58d0f170d948a7' 
  AND token = 'tH1xSWC2IRw2WgXNvCNGVwirK2cKI09VGtPr83EMukA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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