SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8af5829b40239def638513f7b001ce5aba3170fa2152fcc1af4b292b1fc18dc2' 
  AND token = 'ONDydauMtOKNRaUn6c22ZO8DFOjBLwz6KaLHj81ZJkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}