SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4287239eabd6d01575160960db2978d8c0e6e4b68cc2d427f2d015ac8ab24609' 
  AND token = 'wc0lK03nAq2vtqP/1vJtVhE9Q/pgsGgg37qG17f/Ut4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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