SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a02e17ae8b63f97d147f3c539ef31937b17f6732c067ecbfa65d17d9d9c1b0dd' 
  AND token = 'RWKqjxCB+hfcmUkFZrM6JljLbhlYTfGgjEqYC3pH2bw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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