SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9bb7f9d708e446d9badc2bde8a973f7f44e542f21ef19927368556e23a1f7a76' 
  AND token = '1GfJnu28o7J0IADRE4FY1ruqVnhGbH0pfdjVSFvgb/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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