SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4fff3922c58cdee08cfb2d2d25759bb4ad287835e3262757a67b55cacfd9745' 
  AND token = '0OXJA/riYAKFNEUKqRiRSs9pH81yNgYH4EoLwLxhfVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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