SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bfc8e7c09a0f7345f94528629ffb6ad57f206a29b10296a4b778fd6b541ce8d' 
  AND token = 'jXw1D46VGCwUYEhDbnVowWBFwq+gVgP55LZvKhrI1hM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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