SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7b8497ad3455d92f3221e3b0988cb3186be9b8d9c5d73c23ff559f19fd6859df' 
  AND token = 'IpUfYMjG/gKAzhqZ7NDQK9JLAWzHLQvlzzKdGhO8e78=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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