SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c58af27cf50775adbac8085da5cfa369e758529f3b0672716e60435535b12cb5' 
  AND token = 'PvnvikVn2MnfyLwfkk/OmDHuNurxSIIfnbPbtZBHRnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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