SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '229a3c7ada30c92fff6960475c8286d0be2c2983bfe8d4e26d0cade9a0c3536c' 
  AND token = 'WH0mE2UY95Mu4WNgex0zvbhO25tSNL5RhYomS4/rKKY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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