SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f97c3bd64cb9d54f7ac1dcacba5154e1e8dc0804fd2da2e8f5257dfd7696aa33' 
  AND token = 'kPTiksBOESieSPPpMgOkR9xBBXYftXZyEMl3OPetcTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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