SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4dda459e5ecc948ca3c38571249df63d0577e15cdf10fc73c1bde129521948b' 
  AND token = 'O3cdTlGOv2ShNPE0fM/No6y+6h9LSZlTh6wDbweTG0U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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