SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f3bbb8c7d734d47f91d04b219b28f6fa882aa47083ebf8d2c3e4d74feae568a' 
  AND token = 'YA4KYXEpTBMr1/ekAG/UK73hj1tOVMM73a0qehf2dvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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